This invention relates to instruments for positioning body limbs during a medical procedure.
Although the human knee is a very strong joint, the joint can be damaged due to trauma or disease. The knee is a complex joint composed of three articulating surfaces; the two condyles of femur with the corresponding tuberosities of the tibia and the patella with the femur. The bones of the knee are held in place by six exterior ligaments and six interior ligaments and are cushioned from each other by membranous sacks, the bursae. In addition, the semilunar fibro-cartilage deepen the surface of the head of the tibia for articulation with the femur and thereby strengthen the joint. Frequently surgical intervention can correct damage sustained by elements of the knee. For example, bony portions of the knee may be replaced with synthetic components and soft tissue of the knee may be surgically repairable. Typically, an arthroscopic procedure may be used by the surgeon to visualize the joint prior to operating upon the knee joint.
In an arthroscopic procedure, the tip of a fiber-optic arthroscope is inserted into the joint, and by manipulating the leg, that is, moving the lower leg relative to the upper leg, the joint is maneuvered so the surgeon can see, e.g. on a video monitor, the structure of the joint prior to operating on it. Generally, the surgeon performing the arthroscopic procedure holds the leg to be examined by resting the calf of the patient's leg on the iliac crest of the surgeon's hip, or by placing the patient's foot on the femoral region of the surgeon's thigh. The surgeon, by moving his own body up and down and side to side, causes the patient's lower leg to move relative to the patient's thigh, and thereby manipulates the joint for examination or treatment. However, this method of manipulation results in fatigue for the surgeon, since the surgeon is forced to support the weight of the patient's leg while, at the same time, bending over the lower leg to position the arthroscope. Further, since there is no automatic returning of the knee from a valgus, away from the body's midline, or varus, toward the body's midline, manipulation to its normal position, the knee can undergo further damage if the surgeon moves the lower leg at too great an angle relative to the upper leg.
Previous supports for arthroscopic procedures such as described in U.S. Pat. No. 4,407,277 were capable of anchoring the leg in a given position once the leg was placed in the required position. However, these devices were simply braces which did not help the physician in placing the limb into the proper position nor did they return the limb to a normal orientation once the manipulation was complete.
The objectives of the present invention include providing a device that not only will maintain the limb in a predetermined position, but will reduce the stain on a physician in placing the limb in that position and will reduce the risk of overextending and thus further damaging the knee joint.